What is black metal

Metal, is a big family, now the world has 86 kinds of metals. Usually, people put metals into two categories, ferrous and non-ferrous metals. The name of ferrous and non-ferrous metals often let people mistakenly think that black metal must be black, it is not right. There are only three kinds of black metals: iron, manganese and chromium. But three of them are not black! According tometal powder supplier, pure iron is silvery white; Manganese is silvery white; chrome is gray. Because iron surface often rusty, covered with a layer of black iron oxide and brown iron oxide mixture that looked black. No wonder that people call it "black metal". Often say "ferrous metallurgy industry" is mainly refers to the steel industry. Because the most common alloy is manganese and chromium steel, so that manganese and chromium are also considered to be "black metal".

In addition to iron, manganese, chromium, other metals are regarded as non-ferrous metals. In the non-ferrous metals, also have a variety of classifications. For example, according to the proportion, the specific gravity of aluminum, magnesium, lithium, sodium, potassium and the like are less than 5, called "light metals", and the specific gravity of copper, zinc, nickel, mercury, tin, lead and so on are greater than 5, called "heavy metal". Like gold, silver, platinum, osmium, iridium and other are expensive, called "precious metals", radium, uranium, thorium, polonium and so on with radioaction, called "radioactive metal", such like niobium, tantalum, zirconium, lutetium, gold, radium, hafnium, uranium and so on, because of contain less or scattered in earth's crust, it is also known as "rare metal".

Metallurgical industry accustomed to called iron, chromium, manganese and alloys (mainly refers to the alloy and steel) as black metal. In fact pure iron and chromium are silver, and manganese are silver-gray. The reason why they are called black metal is because the steel surface often covered with a layer of black iron oxide, and manganese and chromium are mainly used in smelting steel, so people called iron, chromium, manganese and their alloys as black metal. In addition, people specifically put these three metals and their alloys into a class, and put all the rest and alloys into the non-ferrous metals, it is because steel in the economy occupies an extremely important position, is an important indicator to meature a country's national power; its production accounts for 95% of the world's total metal output. Chromium is the hardest in all metals, and it is also the most difficult corrosion metal. People often add chrome into steel lining, made of hard and corrosion-resistant chromium steel. Chrome steel is a good material for the construction machinery, barrel guns, tanks and armored vehicles. Add more than 12% of chromium in steelmaking, and then mixed into a certain amount of nickel, can make into stainless steel. Chrome also the necessary metal in plating (commonly known as clomiphene). Add about 13% manganese powder in steelmaking, can refine out hard, tough manganese steel. People use manganese steel to manufacture steel mill, ball bearings, bulldozer and excavator buckets and other easy wear parts. High-manganese steel also used to manufacture helmets, tanks armor and armor-piercing warheads.

Source:http://www.mhcmp.com